Electrolytic copper release agent

ABSTRACT

A RELEASE AGENT COMPOSITION APPLIED ON CATHODES PRIOR TO THE ELECTROLYTIC DEPOSITION OF COPPER COMPRISING FROM ABOUT 60-98 VOLUME PERCENT SOLVENT REFINED PARAFFIN OIL HAVING A VISCOSITY OF 50 TO 500 SUS AT 100*F., 0-55 VOLUME PERCENT PARAFFINIC BRIGHT STOCK HAVING A VISCOSITY OF 150-200 SUS AT 210*FF., 0.5-3.0 VOLUME PERCENT OF BUTYL STEARATE, 0.15-0.50 VOLUME PERCENT OF A POUR POINT DEPRESSANT, 0.5-3.0 VOLUME PERCENT OF AN OXYGEN CONTAINING ORGANIC COMPOUND HAVING FROM 1 TO 2 VICINAL EPOXY GROUPS PER MOLECULE. THESE COMPOSITIONS PERMIT THE STRIPPING OF DEPOSITED COPPER WITHOUT DAMAGE TO EITHER THE DEPOSITED COPPER OR TO THE CATHODE.

United States Patent O 3,826,668 ELECTROLYTIC COPPER RELEASE AGENT Howard M. Rue, Media, lPa., assignor to Sun Oil Company of Pennsylvania, Philadelphia, Pa. No Drawing. Filed July 3, 1972, Ser. No. 268,431 lint. Cl. C0811 17/28; C09d 3/00, 3/60 US. Cl. 106-285 Claims ABSTRACT OF THE DISCLOSURE A release agent composition applied on cathodes prior to the electrolytic deposition of copper comprising from about 60-98 volume percent solvent refined paraffin oil having a viscosity of 50 to 500 SUS at 100 F., 0-55 volume percent paraffinic bright stock having a viscosity of 150-200 SUS at 210 F., 0.5-3.0 volume percent of butyl stearate, 0.15-0.50 volume percent of a pour point depressant, 0.5-3.0 volume percent of an oxygen containing organic compound having from 1 to 2 vicinal epoxy groups per molecule. These compositions permit the stripping of deposited copper without damage to either the deposited copper or to the cathode.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to the electrolytic refining of copper. More particularly it refers to a new release agent useful in the electrolytic refining of copper.

2. Description of the Prior Art It is conventional in the electrolytic refining of copper to coat the cathode, which is a sheet of hard-rolled copper called a starting sheet, or starting blank with a release agent to facilitate the stripping of the deposited copper. Release agents generally used are light petroleum oil containing animal oils, vegetable oils, fatty acids and esters of fatty acids.

While the overall operation with these release agents is generally satisfactory there has been some removal problems of the deposited copper with severe sticking, resulting in damage to the deposited copper sheets and cathodes with subsequent loss of production and the additional expense of repairing or replacing the damaged cathodes. Therefore, there has been a need for a more effective release agent.

SUMMARY OF THE INVENTION I have now found a release agent composition when applied on cathodes of an electrolytic copper refining cell prior to electrolysis permits the stripping of the deposited copper without damage to the deposited copper or the cathode. This release agent comprises: (a) 40-98 volume percent of solvent refined paraffin oil having a viscosity of 50-500 SUS at 100 F., (b) 0-55 volume percent paraffinic bright stock having a viscosity of 150-200 SUS at 210 F., (c) 0.5-3.0 volume percent of butyl stearate, (d) 0.5-1.5 volume percent of a pour point depressant, (e) 0.5-3.0 volume percent of an oxygen-containing organic compound having about 8-30 carbon atoms containing from 1 to 2 vicinal epoxy groups per molecule.

DESCRIPTION OF THE PREFERRED EMBODIMENT In accordance with this invention, the uniquecombination of butyl stearate, pour point depressant, and oxygencontaining organic compound having 8-30 carbon atoms containing from 1 to 2 vicinal epoxy groups per mole when added to a base oil is superior to any conventional release agent used on cathodes in the electrolytic copper refining cell.

Practice of the invention thus involves coating the cathode prior to immersion in the electrolyte, which is a solution generally containing copper sulfate and sulfuric acid. The release agent composition of this invention does not contaminate the electrolyte or in any way adversely affect the cathode deposit or the efficiency of the electrolytic operation.

The base oil to which the other materials are added is solvent refined paraffin oil having a viscosity of 50 to 500 SUS at F. and preferably 60 to 100 SUS at 100 F. This paraffin oil may be used alone but preferably is blended with from about 1-55 volume percent of a paraffinic bright stock having a viscosity of 200 SUS at 210 F. and preferably 20-40 volume percent having a viscosity of -180 SUS at 210 F. The viscosity of the base oil or blended oil should be chosen so that the finished viscosity of the release agent should be between 100-500 SUS at 100 F. and preferably between 180-250 SUS at 100 F.

Any suitable procedure may be used for incorporating the additives of the base oil. Generally, the desired quantity of butyl stearate is dissolved into the blended oil at 70 to 110 F. followed by the addition of the oxygencontaining organic compound and the pour point depressant using a simple propellor type of agitator. No furr ther treatment is required and the composition may be used immediately for practicing the invention or may be stored for future use.

Pour point depressants are well known, and a wide range thereof can be used in the compositions of the present invention. Pour point depressants especially suitable for preparing the compositions of the present invention are prepared by condensing a derivative of paraffin wax with an aromatic compound. For example, parafiin wax can be chlorinated and the chlorinated wax condensed with an aromatic compound such as naphthalene, toluene, benzene, phenol, phthalic anhydride, or the like, using the Friedel-Crafts reaction. Aluminum chloride is an especially good catalyst to employ but other catalysts known to be effective in such reactions, such as ferric chloride, stannic chloride, and the like, can be used. The pour point depressants can also be prepared by dechlorinating chlorinated wax and condensing the resulting unsaturated material with the same aromatic hydrocarbons, i.e., with naphthalene, toluene, benzene, phenol or phthalic anhydride. Other aromatic compounds which can be employed include, for example, aniline, xylene, ethyl benzene, cresol, methyl naphthalene, and homologues thereof.

Suitable pour point depressants are typified by Paraflow manufactured by the Standard Oil Company of New Jersey, New York, New York and Stanopour produced by Mansanto Chemical Company, St. Louis, Missouri. Also, esters of methacrylic acid and higher fatty alcohols such as cetyl or lauryl may be used. These are marketed by the Rohm and Haas Company, Philadelphia, Pennsylvania, under the trade name Acryloid.

The oxygen-containing organic compound having about 8-30 carbon atoms containing from 1 to 2 vicinal epoxy groups per mole are useful in the present invention. For example, epoxy derivatives of the higher alkenes and dienes, glycidyl esters and glycidyl ethers. Suitable oxygencontaining organic compounds are the epoxy derivatives of octeue, octadiene, nonene, nonadiene, etc., also, the glycidyl esters and ethers of octaine, nonane, decane, dodecanes, cetane, octadecane etc. Exemplaryof the above are the lower alkyl esters of epoxidized castor oil, e.g., acetyl to butyl and Epoxide No. 7, which is a glycidyl ether of c -c carbon range, produced by the Procter and Gamble Company, Cincinnati, Ohio.

The following examples presented herein are intended to be merely illustrative and are not intended to limit the scope of the claims. Certain ratios of ingredients have 'been specified. It is to be understood that those skilled in the art will be able to select the respective proportion from each range so as to produce compositions Within the spirit and scope of the invention as disclosed. The examples provide a guideline to indicate to those skilled in the art the means and manner of ingredient selection and procedures for utilizing the compositions obtained.

EXAMPLE I A cathode release agent composition was prepared by adding 60 volume percent of a 70 SUS/100 F. solvent refined parafiin oil to a propellor mixing kettle and adding 37.65 volume percent of a 165 SUS/210 F. parafiinic bright stock, 1.00 volume percent of butyl stearate, 0.35 volume percent of Parafiow 149 and 1.00 volume percent Epoxide No. 7 and mixing for 15-30 minutes at 80-90" F.

EXAMPLE II 97.65% 200-300 SUS/100 F. solvent refined paraffin oil, 1.00 volume percent butyl stearate, 0.35 volume percent Parafiow 149 and 1.00 volume percent of Epoxide No. 7.

EXAMPLE 111 97.65% 200-300 SUS/ 100 F. solvent refined paraffin oil, 0.35 volume percent Paraflow 149, 2 volume percent acetylated epoxidized castor oil.

EXAMPLE IV 60 volume percent 60-100 SUS/100 F. solvent refined parafiin oil, 37.65 volume percent 150-200 SUS/210 F. solvent refined bright stock, 0.35 volume percent Paraflow 149, 2.00 volume percent butyl ester of epoxidized castor oil.

EXAMPLE V 60 volume percent of 60-100 SUS/100 F. solvent refined parafiin oil, 37.65 volume percent of 150-200 SUS/ 210 F. solvent refined bright stock, 0.35 volume percent of Paraflow 149, and 1.00 volume percent of dodecanc epoxide.

The invention claimed is:

1. A composition for use as a relase agent on cathodes of an electrolytic copper refining cell which permits the stripping of the deposited copper without damage to either the deposited copper or the cathode comprising:

(a) 60-98 volume percent solvent refined parafiin oil having a viscosity of 50 to 500 SUS at 100 F.,

(b) -55 volume percent parafiinic bright stock having a viscosity of 150-200 SUS at 210 F.,

(c) 0.5-3.0 volume percent butyl stearate,

(d) g.15-1.5 volume percent of a pour point depressant (e) 0.5-3.0 volume percent of an oxygen-containing organic compound having 8-30 carbon atoms containing from 1 to 2 vicinal epoxy groups per molecule.

2. A composition according to Claim 1 containing about 60-80 volume percent refined parafiin oil having a viscosity of 60-100 SUS at 100 F. and containing about 20-40 volume percent parafiinic bright stock having a viscosity of 160-180 SUS at 210 F.

3. A composition according to Claim 1 containing about volume percent solvent refined parafiin oil having a viscosity of 60-80 SUS at F. and about 35-38 volume percent parafiinic bright stock having a viscosity of -180 SUS at 210 F.

4. A composition according to Claim 1 wherein said oxygen-containing organic compound is selected from the group consisting of glycidyl ether having a carbon range of C -C acetyl ester of epoxidized castor oil, butyl ester of epoxidized castor oil and dodecane epoxide.

5. A composition according to Claim 4 containing about 1 volume percent of said oxygen-containing compound.

6. A composition according to Claim 4 wherein said oxygen-containing compound is the glycidyl ether of C C carbon range.

7. A composition according to Claim 2 containing about 1 volume percent of glycidyl ether of C -C carbon range.

8. A composition according to Claim 4 wherein said oxygen-containing compound is the acetyl ester of epoxidized castor oil.

9. A composition according to Claim 4 wherein said oxygen-containing compound is the butyl ester of epoxidized castor oil.

10. A composition according to Claim 4 wherein said oxygen-containing compound is dodecane epoxide.

References Cited UNITED STATES PATENTS 3,285,755 11/1966 Airola 106-285 2,834,731 5/1958 Carpenter et al 106-311 3,470,001 9/1969 Koury 106-2 2,349,044 5/ 1944 Jahn 106-285 2,661,296 12/1953 Knapel et al 106-14 2,703,783 3/1955 Popkin 106-285 3,285,755 7/1963 Airola 106-14 3,046,203 7/1962 Cadwell 204-281 2,703,783 3/1955 Popkin 252-29 2,186,018 1/1940 Griesinger 106-285 2,285,762 6/1942 Tuwiner et al 204-290 R 2,834,731 5/1958 Carpenter 106-311 2,661,296 12/1953 Schiermeier et a1 106-14 3,470,001 9/ 1969 Koury 106-2 2,471,638 5/ 1949 McCarthy 106-245 2,836,499 5/1958 Lyons 106-243 OTHER REFERENCES See also 2,928,752, Felletschin et al. Mar. 15, 1960, 106-285.

JOSEPH L. SCHOFER, Primary Examiner T. S. GRON, Assistant Examiner US. Cl. X.R. 

